Alkaline Phosphatase Based Amperometric Biosensor Immobilized by Cysteamine-Glutaraldehyde Modified Self-Assembled Monolayer


YORGANCI E., AKYILMAZ E.

ARTIFICIAL CELLS BLOOD SUBSTITUTES AND BIOTECHNOLOGY, vol.39, no.5, pp.317-323, 2011 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 39 Issue: 5
  • Publication Date: 2011
  • Doi Number: 10.3109/10731199.2011.563363
  • Title of Journal : ARTIFICIAL CELLS BLOOD SUBSTITUTES AND BIOTECHNOLOGY
  • Page Numbers: pp.317-323

Abstract

Alkaline phosphatase (ALP) was immobilized with cross-linking agents glutaraldehyde and cysteamine by forming a self-assembled monolayer on a screen printed gold electrode. ALP converts p-nitrophenyl phosphate to p-nitrophenol and phosphate. p-Nitrophenol loses H(broken vertical bar) ion and turns into the negatively charged compound p-nitrophenolate at medium pH. As a result, the unstable product formed is measured chronoamperometrically at an application potential of + 0.95 V. The biosensor response depends linearly on p-nitrophenyl phosphate concentration between 0.05 - 0.6 mM with a response time of 40 seconds. Detection limit of the biosensor is 0.033 mM.